Why was the word "ترجعونها" (you restore it) used instead of "فارجعوها" (then restore it) in verse 87 of Surat Al-Waqi'ah, and why was the vocative particle omitted in His saying, Exalted is He: "يوسف أعرض عن هذا" (Joseph, turn away from this)?

The meaning of "Why do you not restore it, if you are truthful?" is: Why do you not restore the soul, when it has reached the throat, back to its place, if you are not to be held accountable? The word "lawla" (why not) here is for urging, and it does not precede an imperative verb. As for the omission of the vocative particle in "Joseph, turn away from this," it is because the one being addressed is near, and it conveys closeness and tenderness towards him.